Manufacturing method of single crystal and apparatus of manufacturing the same

ABSTRACT

In a single crystal manufacturing method by a horizontal magnetic field applied CZ method wherein coils are disposed interposing a crucible coaxially with each other, the coils constituting superconductive electromagnets of a magnetic field application apparatus and the silicon crystal is pulled from melt in the crucible while applying a horizontal magnetic field to the melt; an elavation apparatus capable of finely adjusting relative positions of the superconductive electromagnets and the crcucible in a vertical direction is disposed. The descent of a central portion Cm in a depth direction of the melt is canceled by elevating the crucible with the elevating apparatus, the descent being accompanied with proceeding of process of pulling the single crystal, thereby a coil central axis Cc of the superconductive electromagnets always passes through the central portion Cm or below this portion. Compared with the conventional HMCZ method, an uniformity of an intensity distribution of the magnetic field applied to the melt is increased so that a suppression effect on the melt convection all over the crucible is enhanced.

This application is a divisional of 08/655208, filed May, 30, 1996, nowU.S. Pat. No. 5,792,255.

The present disclosure relates to subject matter contained in Japanesepatent application No. 158454/1995 (filed on Jun. 1, 1995).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a manufacturing method of a singlecrystal and an apparatus of manufacturing the same, more particularly toa horizontal magnetic field applied CZ method (hereinafter referred toas a HMCZ method) wherein while applying a horizontal magnetic field toa raw material melt in a crucible with a magnetic field applicationapparatus, a single crystal is pulled from the melt, and an apparatussuitable for carrying out this manufacturing method.

2. Description of the Prior Art

It has been well known that the foregoing HMCZ method is superior to anordinary Czochralski method (hereinafter referred to as a CZ method) invarious respects. An apparatus used for the execution of the HMCZ methodis an improvement of the apparatus used in the ordinary CZ method,wherein a pair of magnetic field application apparatuses, eachcomprising an electromagnet such as a superconductive magnet, aredisposed facing each other interposing a crucible in the outside of aheater for heating the crucible.

When a silicon single crystal is, for example, pulled from a siliconmelt in a quartz crucible, the thermal convection of the silicon melt issuppressed according to the HMCZ method, and the fluctuations of atemperature with time in the surface portion of silicon melt(temperature of interface between solid and liquid) is greatly reduced,and, at the same time, a dissolution amount of SiO from the crucible isreduced. As a result, the generation of defects and dislocations issuppressed, and, moreover, the silicon single crystal with uniformityand low oxygen concentration can be easily obtained.

U.S. Pat. No. 4,565,671 discloses an example of a single crystalmanufacturing apparatus using the HMCZ method. This apparatus isdesigned such that the central axis of a superconductive coil is inaccord with the surface of the melt in the quartz crucible so that thethermal convection near the surface of the melt is suppressed and thethermal convection area is formed below the vicinity of the surface ofthe melt.

In this apparatus, the heat transfer to the interface layer between thesingle crystal during being pulled and the melt is enhanced so that thetemperature difference between the crucible periphery and theaforementioned interface layer can be reduced. At the same time, themelt which is fully agitated below the vicinity of the surface thereof,is supplied to the aforementioned interface. Therefore, the singlecrystal with the more uniform property compared to that obtained by theapparatus according to the ordinary CZ method can be grown. In addition,the crack of the crucible produced by thermal stress can be prevented.

There are two subjects to be solved on the single crystal growthtechnique required for the recent single crystal, especially for siliconsingle crystal, of a large diameter. One is a low oxygen concentration,and the other is an increase in productivity owing to a stable crystalgrowth. Recent years, the device manufacturing processes have beenconducted in cleaner environment than before so that the necessity forthe gettering effect for heavy metal impurities within the wafer islessened. Therefore, the demand for a single crystal of a low oxygenconcentration has been increased.

However, as the diameter of the single crystal becomes larger, thediameter of the quartz crucible used for the growth the single crystalbecomes larger. As a result, the dissolution amount of the inner surfacelayer of the crucible to the melt in the crucible increases so that theoxygen concentration in the melt becomes higher. Thus, the oxygenconcentration in the single crystal of a large diameter is liable to behigh compared to that of a small diameter obtained by a small-sizedcrucible.

As factors that the dissolution amount of the quartz crucible innersurface into the melt increases as the diameter of the single crystalbecomes larger, (a) the increase in a friction force, when the cruciblerotates, due to the tendency of the weight of the melt to grow larger,(b) the increase in the heating amount required for heating the crucibleaccompanied with the tendency of the crucible diameter to grow larger,and (c) the increase in the melt convection in the melt due to theincrease of temperature difference in the melt are given. Therefore, toreduce the oxygen concentration in the single crystal of a largediameter, it is very essential to suppress the convection of the melt inthe crucible.

In the manufacturing apparatus of the single crystal disclosed in theforegoing United States Patent, however, the uniformity of thehorizontal magnetic field applied to the melt is not necessarilysatisfactory. Therefore, the suppression effect on the melt convectionin the crucible is not necessarily sufficient. For this reason, when thesilicon single crystal of the diameter larger than 8 inch is pulled,there has been a drawback that it is difficult to obtain the productwith an uniformly low oxygen concentration and less defects.

Furthermore, in the manufacturing apparatus of the single crystaldisclosed in the foregoing United States Patent, though the convectionin the vicinity of the surface of the melt in the crucible issuppressed, the apparatus is designed such that the thermal convectionunder the vicinity of the surface is present. Therefore, the convectionat the lower portion of the crucible is large likewise the conventionalapparatus, so that the dissolution and corrosion of the quartz crucibleproceed excessively and the lifetime of the crucible is shortened.

SUMMARY OF THE INVENTION

The present invention was made considering the foregoing problems. Theobject of the present invention is to enhance the suppression effect onthe melt convection in the crucible and to manufacture the largediameter single crystal with the uniform and low oxygen concentration,and less defects, by improving the manufacturing method and apparatus ofthe single crystal according to the HMCZ method.

Another object of the present invention is to reduce the number of thecrucibles used for pulling single crystal by prolonging the lifetime ofthe crucible, resulting in the reduction of the time required to replacethe crucible.

According to a manufacturing method of a single crystal of the presentinvention, in a HMCZ method wherein a pair of coils constitutingelectromagnets, e.g., superconductive magnets of a magnetic applicationappratus are disposed interposing a crucible coaxially with each other,and a single crystal is pulled from a raw material melt in the cruciblewhile applying a horizontal magnetic field to the melt, the improvementwherein the vertical positions of the electromagents relative to thecrucible are determined such that central axes of the coils constitutingthe electromagnets pass through the central portion of the melt in thedepth direction thereof or the portion lower than the central portionthereof.

In the manufacturing method of the single crystal according to thepresent invention, the single crystal should be preferably pulled whilekeeping the distance in a horizontal direction between theelectromagenet and the crucible constant. Furthermore, the variationwidth of the horizontal magnetic field intensity in the depth directionof the melt should be desirably controlled within the range of 0.8 to1.2 times as wide as the average value of the horizontal magnetic fieldintensity in the depth direction of the melt on all of linesperpendicular to the surface of the melt, more preferably, 0.85 to 1.15times.

The manufacturing method of the single crystal according to the presentinvention is not limited to the single crystal pulling method in a batchprocess according to the ordinary CZ method, and is also applicable to asingle crystal pulling method according to a so-called Recharge CZ(RCCZ) method or a Continuous Charging (CCCZ) method.

In the RCCZ method, without solidifying a residual melt in a crucibleafter completion of a single crystal growth, pulling operations arerepeated by refilling a raw material in the crucible so that a pluralityof single crystal rod can be grown sequentially from the same cruciblein the batch process.

In the CCCZ method, either a raw material melt or a granularpolycrystalline raw material is charged in a crucible continuously. Bykeeping the amount of a melt in the crucible constant, the singlecrystal growth is continuously performed (see "Semiconductor SiliconCrystal Technology" Fumio SHIMURA, Published by Maruzen).

To execute the present invention following the RCCZ method, theforegoing horizontal magnetic field application apparatus may beattached to the conventional puller according to the RCCZ method.

To execute the present invention following the CCCZ method, theforegoing horizontal magnetic field application apparatus may beattached to the conventional puller according to the CCCZ method.

When a manufacturing method of a single crystal according to the presentinvention is executed following the ordinary CZ or RCCZ method, in orderto set the positions of electromagnets relative to a crucible so thatcoil central axes of the electromagnets pass through the central portionin a depth direction of melt in the crucible, after the positions of theelectromagnets relative to the crucible to the crucible in a verticaldirection are set at the beginning of growing a single crystal so thatcoil central axes of the electromagnets pass through the above centralportion, and by elevating the crucible continuously, the descent of theaforementioned central portion of the melt accompanied with the pullingof the single crystal should be canceled.

It is noted that in the foregoing canceling operation, theelectromagnets may be descended continuously on behalf of the elevationof the crucible. Furthermore, when the manufacturing method of thesingle crystal according to the present invention is applied to the CCCZmethod, the foregoing operation is unnecessary because of the constantheight of the melt surface in the CCCZ method.

In order to suppress the melt convection in the crucible following theHMCZ method, it is important that the magnetic field having as highuniformity and intensity as possible should be applied to the whole ofthe melt by disposing the melt in the crucible in the magnetic field ofa gentle intensity gradient and a high intensity. To accomplish this, itis effective that the electromagnet of a large coil diameter Rc (seeFIG. 1) capable of producing the high intensity electric field isdisposed at a position far distant from the crucible.

According to a manufacturing apparatus of a single crystal of thepresent invention, in a single crystal manufacturing apparatus used forthe horizontal magnetic field application CZ method wherein coilsconstituting electromagnets, e.g., superconductive magnets, of amagnetic field application apparatus are disposed interposing a cruciblecoaxially with each other, and the single crystal is pulled from a rawmaterial melt in the crucible while applying a horizontal magnetic fieldto the melt, the improvement wherein an elevating mechanism is disposedwhich is capable of finely adjusting the vertical position of theaforementioned electromagnet relative to the aforementioned crucible.

In the single crystal manufacturing apparatus of the present invention,the electromagnets should be preferably capable of producing a highintensity magnetic field, and the coil diameter Rc should be preferablythree times as long as the depth of the melt in the crucible at thebeginning of the single crystal growth. In addition, it is morepreferable that the electromagnets which form the same intensitydistribution of the magnetic field are disposed symmetrically withrespect to a central axis of the crucible and at a far distance from thecrucible.

The manufacturig apparatus of this invention will be described by usingFIG. 1. In this apparatus, a pair of superconductive electromagnets 12and 15 having the same specification are disposed symmetrically withrespect to the central axisl of the crucible 2, and the verticalpositions of the superconductive electromagnets relative to the crucible2 is adjusted by the foregoing elevating mechanism (not shown), therebyduring the processes of pulling the single crystal, the coil centralaxis Cc always passes through the the central portion Cm of the melt inthe crucible 2 in the depth direction thereof or below the portion Cm.Specifically, the operation in the apparatus of the present inventiondiffers simply from that in the conventional HMCZ method in that theapparatus of the present invention is controlled such that the foregoingcoil central axis Cc passes through the foregoing central portion Cm orbelow the portion Cm.

In the processes of the single crystal growth, the isointensity linedistribution of the magentic field formed by the superconductiveelectromagnets 12 and 15 is illustrated in FIG. 3. The intensity of themagnetic field applied to the melt 41 in the crucible decreases, as thedistance of the portion of the melt from the superconductiveelectromagnets 12 and 15 increases. For instance, the magnetic fieldintensities at the curves 1a and 1c are 6000 Gauss, and the curves 1band 1d, 4000 Gauss. For this reason, the magnetic field intensityapplied to the melt 41a shown with the hatching is not more than 4000Gauss, and the magnetic field intensity at the melt 41b other than themelt 41a is more than 4000 Gauss and not more than about 6000 Gauss.Strictly describing, the magnetic field intensity at the melt closest tothe inner wall of the crucible 2 exceeds 6000 Gauss.

In this case, in the manufacturing apparatus of the single crystal, thesuperconductive electromagnets 12 and 15 of the same magnetic fieldintensity distribution are disposed symmetrically with respect to thecrucible central axis 1 and at the positions far from the crucible 2,which is capable of generating the magnetic field of a high intensityand have the coil diameter Rc more than three times as long as the depthof the melt in the crucible at the beginning of pulling the singlecrystal. Thus, the ratio of the melt 41a shown with the hatching to thetotal amount of the melt can be greatly reduced. As a result, it ispossible to place almost the total amount of the melt in the crucible atthe magnetic field intensity ranging from 4000 to 6000 Gauss.

Therefore, according to the manufacturing apparatus of the singlecrystal of the present invention, an effective dynamic viscositycoefficient of the melt in the crucible is increased, and effectivedynamic viscosity coefficients of all of the melt are practically equalso that the convection of the melt in the crucible can be effectivelyrestrained. Hence, the variation in a temperature of the melt during theprocesses of pulling the single crystal is restrained. Furthermore,since the convection of the melt at the bottom of the crucible iseffectively restrained, the disolution and corrosion of the crucible bythe melt are hard to occur thereby the lifetime of the crucible isprolonged.

By keeping the horizontal distance between the aforementionedelectromagnet and the aforementioned crucible constant, the changingwith passage time of the intensity distribution of the magnetic fieldapplied to the melt can be removed, so that the suppression effect onthe melt convection in the crucible can be further increased.

The reason why the variation width of the horizontal magnetic fieldintensity in the depth direction of the melt in the crucible should bepreferably controlled at the range of 0.8 to 1.2 times (more preferably,0.85 to 1.15 times) as much as the average value of the horizontalmagnetic field intensity in the depth direction of the melt on all oflines perpendicular to the surface of the melt is as follows.Specifically, when the superconductive electromagnet is used as theelectromagnet and the magnetic field of the intensity of about 5000Gauss is applied to the melt in the crucible, if it is considered that agreat decrease in the electric power consumption efficieny and anincrease in size of the manufacturing apparatus of the single crystalshould be avoided, the desirable variation width of the horizontalmagnetic field in the depth direction of the melt is in the foregoingrange. If the variation width is in this range, the suppression effecton the melt convection is most enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way ofexample and with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic vertical cross-sectional view showing aprincipal structure of an apparatus of manufacturing a single crystalaccording to an embodiment of the present invention;

FIG. 2 is a horizontal cross-sectional view of FIG. 1;

FIG. 3 is an isointensity line distribution of a magnetic field in atesting example 1, with a partly vertical cross-sectional view of theapparatus in FIG. 1; and

FIG. 4 is an explanatory diagram showing a melt located at a magneticfield not more than 4000 Gauss in the comparative example 1, andcorresponds to FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will be now described withreference to the accompanying drawings below.

EMBODIMENT I

FIG. 1 is a diagrammatic vertical cross-sectional view showing aprincipal structure of a silicon single crystal puller. FIG. 2 is ahorizontal cross-sectional view of FIG. 1.

In this single crystal puller, a crucible 2 having an inner side formedof quartz and an outer side formed of graphite is supported, in acylindrical chamber 1 formed of stainless steel, by a supporting shaft 3extending in a vertical direction. A cylindrical heater 4 formed of acarbon material is disposed around the crucible 2, and a cylindricalheat insulator 5 formed of a carbon material is disposed around theheater 4. The heater 4 and the heat insulator 5 are fixed at theirpositions in vertical and horizontal directions.

The supporting shaft 3 is allowed to rotate together with the crucible 2by a rotation driving mechanism (not shown) and the number of itsrotations can be finely adjusted. Furthermore, the supporting shaft 3 isallowed to move upward and downward by a sliding mechanism (not showncomprising a control mechanism, the sliding mechanism corresponding tothe foregoing elevating mechanism, and its positions in the up and downdirections can be finely adjusted.

At the outside of the chamber 1, a magnetic field application apparatus13 and a magnetic field application apparatus 15 are disposedsymmetrically with respect to the central axis of the crucible 2. Themagnetic field application apparatus 13 comprises a cooling container 11and a superconductive electromagnet 12 accommodated in the container 11.The magnetic field application apparatus 15 comprises a coolingcontainer 11 and a superconductive electromagnet 15 accommodated in thecontainer 11. The distances from the crucible 2 and positions in the upand down directions of these superconductive electromagnets 12 and 15are kept constant. The coil diameters Rc of the superconductiveelectromagnets 12 and 15 are three times as long as the depth of themelt in the crucible when the pulling of the single crystal is begun.

A cylindrical stainless pulling chamber 21 is arranged above the chamber1, coaxially with the chamber 1 connected to the chamber 21. Anisolation valve 22 is disposed at the connection portion of the chamber1 and the pulling chamber 21. The pulling chamber 21 forms a space foraccommodating the silicon single crystal pulled and for taking out it tothe outside.

A winding up apparatus (not shown) for the silicon single crystal isarranged above the pulling chamber 21 such that it is capable ofrotating around the vertical axis. A wire 23 is hung from the winding upapparatus, and a seed crystal 25 is attached to the lowermost part ofthe wire 23 by a seed crystal holder 24. An inlet 31 of inert gas suchas Ar is formed in the upper portion of the pulling chamber 21, and anoutlet 32 for inert gas is formed in the lower portion of the chamber 1.The outlet 32 is connected to a vacuum generator (not shown) such thatthe chamber 1 and the pulling chamber 21 are kept at a predeterminedvacuum. It is noted that reference numeral 41 denotes a silicon melt,and 42, a silicon single crystal during being pulled.

When growing the silicon single crystal, the positions of thesuperconductive electromagnets 12 and 15 relative to the crucible 2 inthe up and down directions is determined by the foregoing slidingmechanism before starting the pulling of the single crystal, such thatthe central axis Cc of the magnets 12 and 15 passes through the centralportion Cm in the depth direction of the melt 41 or passes through belowthe central portion Cm. Then, the superconductive electromagnets 12 and15 are operated and the heater 4 starts to heat the side wall of thecrucible 2. Subsequently, the seed crystal 25 attached to the seedcrystal holder 24 is immersed in the surface of the melt 41, inert gassuch as Ar is supplied to the surface of the melt 41, and the crucible 2is rotated. At the same time, the seed crystal 25 is pulled upwardlywhile rotating the seed crystal 25, so that a neck, a cone, a shoulder,and a main body are sequentially grown.

As the growing of the single crystal proceeds, the depth of the melt 41is reduced, so that the foregoing central portion Cm falls gradually.For this reason, in this embodiment, the crucible 2 is continuouslyelevated by the foregoing sliding mechanism thereby the fall of thecentral portion Cm can be canceled. By the above operation, thesuperconductive electromagnets 12 and 15 are regulated such that thecoil central axis Cc always passes through the central portion Cm orbelow the portion Cm.

[Testing Example I]

Next, a pulling test of a silicon single crystal by a batch processexecuted according to the foregoing manner, which uses the apparatus ofFIG. 1, will be described.

(1) Specification of the puller:

I. an inner diameter of the crucible 2: 600 mm

II. a depth of the crucible 2: 400 mm

III. an outer diameter of the heater 4: 750 mm

IV. coil diameters Rc of the superconductive electromagnets 12 and 15:840 mm

V. a distance D between the superconductive electromagnets 12 and 15:1500 mm

(2) Pulling conditions:

I. a diameter×a length of the silicon single crystal (a main body) to beobtained: 8 inch×1.2 m, 9 inch×1 m

II. the number of rotations of the crucible 2: 0.6 rpm (constant)

III. the number of rotations of the seed crystal: 15 rpm (constant androtated in an opposite direction to the crucible)

IV. a depth of the melt 41 in the crucible 2 at the beginning of thepulling of the single crystal: 260 mm

V. the others: keep the pressure in the chamber 1 at not more than 300mbar while supplying a suitable amount of inert gas (Ar)

An isointensity line distribution of the magnetic field formed by thesuperconductive electromagnets 12 and 15 is shown in FIG. 3. Theisointensity line distribution was not varied all over the processes ofthe pulling of the single crystal. The right and left contour lines ofthe melt 41a were in accord with the isointensity line at 4000 Gauss ofthe magnetic field. Most of the other melt 41b were present between theisointensity line at 4000 Gauss of the magnetic field and theisointensity line at 6000 Gauss thereof. As a result, the intensitiy ofthe magnetic field applied to the melt 41a was not more than 4000 Gauss,and the intensity of the magnetic field applied to the melt 41b was morethan 4000 and not more than about 6000 Gauss. Furthermore, the ratio ofthe volume of the melt 41a to the volume of the whole melt could begreatly reduced.

The ratio of the amount of the melt shown by hatching to the amount ofthe whole melt can be greatly reduced all over the pulling process ofthe single crystal by the foregoing puller and the foregoing pullingmethod. Most of the whole melt in the crucible can be located at themagnetic field of the intensity 4000 to 6000 Gauss. Though thesuppression effect on the melt convection 41a is somewhat inferior tothat in the portion 41b, the magnetic field intensity of the melt 41a isnot lowered so much. In addition, the ratio of the melt 41a to the melt41b is small. Therefore, the deterioration of the crucible due to themelt convection can be suppressed. This gives an advantage that thecrucible can be used for long time with the application of the presentinvention to the RCCZ method or the CCCZ method.

The silicon single crystals of 8 and 9 inch diameters obtained in thetest example I had an oxygen concentration of about 10 ppma (JEIDA), anda large diameter silicon single crystal having a very low oxygenconcentration compared to the conventional HMCZ method could beobtained. Furthermore, these silicon single crystals had an oxygenconcentration with a high uniformity in radial direction. Themicroscopic uniformity in the direction of the single crystal growthaxis good.

[Comparative Example I]

Next, in this comparative example I the apparatus of FIG. 1 was used.The comparative example I was different from the testing example I onlyin that the coil central axis Cc of the superconductive electromagnets12 and 15 was disposed just below the surface of the silicon melt 51 andclose to the surface of the silicon melt, during all of the process ofthe pulling of the silicon single crystal. On the above condition, thesilicon single crystal of the same dimension as that of the testingexample I was grown. The magnetic field applied to the melt 51 is shownin FIG. 4. FIG. 4 is prepared using partly the isointensity linedistribution of the magnetic field.

According to this method, during all of the process of the growth of thesingle crystal, the ratio of the hatched melt 51a, which was close tothe central axis of the crucible 2, to the total amount of the wholemelt was considerably larger compared with the testing example 1 asshown in FIG. 4. However, also in this case, the intensity of themagnetic field applied to the melt 51a was not more than 4000 Gauss, andthe intensity of the magnetic field applied to the melt 51b other thanthe melt 51a was more than 4000 Gauss and not more than about 6000Gauss.

In this pulling apparatus and method, since it was impossible to reducethe ratio of the hatched melt to the whole melt, it was impossible todispose most of the whole melt in the crucible at the range of themagnetic field intensity ranging from 4000 to 6000 Gauss, unlike thetesting example I. Furthermore, the ratio of the hatched melt 51a wherethe magnetic field is weak has been large, and the magnetic fieldintensity in the vicinity of the center of the portion where themagnetic field is weak has been small compared with the foregoingtesting example I, so that the deterioration of the crucible due to theconvection of the melt has been large and the number of the cruciblesused for the pulling of the single crystal has been increased.Therefore, the application of the apparatus of the comparative example Ito the RCCZ method and the CCCZ method produces the problems.

The silicon single crystals of 8 and 9 inch diameters obtained in thecomparative example I had an oxygen concentration of about 13 ppma(JEIDA). The uniformity of the oxygen concentration in radial directionof these single crystals and the microscopic uniformity in the directionof the single crystal grows axis were inferior.

As is clear from the above description, according to a manufacturingmethod of a single crystal of the present invention, in a HMCZ methodwherein coils constituting electromagnets of magnetic applicationapparatus are disposed interposing a crucible coaxially with each other,and a single crystal is pulled from the raw material melt in thecrucible while applying a horizontal magnetic field to the melt, theimprovement wherein the vertical positions of the electromagentsrelative to the crucible are determined such that the central axes ofthe coils constituting the electromagnets passes through the centralportion of the melt in the depth direction thereof or the portion lowerthan the central portion thereof. According to the present invention,the magnetic field of a narrow intensity range can be applied to most ofthe whole melt in the crucible all over the process of the singlecrystal growth. In other words, compared with the conventional HMCZmethod, the uniformity of the intensity distribution of the magneticfield applied to the melt in the crucible can be enhanced.

As a result, the suppression effect on the melt convection in thecrucible is remarkably raised, and the single crystal of a largediameter with less defects can be stably manufactured.

Furthermore, since the melt convection at the bottom of the crucible iseffectively retrained, the melt hardly corrodes the crucible thereby thelifetime of the crucible can be prolonged. Accordingly, the number ofthe crucibles needed for the amount of the pulled the single crystal canbe reduced.

Furthermore, in the manufacturing apparatus of the single crystal of thepresent invention wherein coils constituting electromagnets of anelectric field application apparatus are disposed interposing a cruciblecoaxially with each other, a single crystal is pulled from a rawmaterial melt in the crucible while applying a horizontal magnetic fieldto the melt, the improvement wherein an elevating apparatus capable offinely adjusting the vertical position relative to the crucible isarranged, the descent of a central portion of the melt in the depthdirection can be canceled by elevating the crucible with the elevatingapparatus.

According to the present invention, the central axes of the coils of theelectromagnets always passes through the central portion of the melt orbelow the central portion, during the processes of the single crystalgrowth.

What is claimed is:
 1. In a manufacturing apparatus of a single crystalby a horizontal magnetic field applied CZ method wherein a pair of coilsconstituting electromagnets of a magnetic field application apparatusare disposed interposing a crucible coaxial between the coils, and meansfor pulling the single crystal from a raw material melt in the cruciblewhile applying the horizontal magnetic field to the melt,wherein thevertical portions of the electromagnets relative to the crucible aredetermined such that central axes of the coils Cc constituting theelectromagnets pass through the central portion of the melt Cm in adepth direction thereof or the lower portion in a depth direction thanthe central portion Cm thereof.
 2. A manufacturing apparatus of a singlecrystal according to claim 1, wherein an elevating apparatus is disposedwhich is capable of finely adjusting the vertical position of saidelectromagnets relative to said crucible.
 3. A manufacturing apparatusof a single crystal according to claim 1, wherein electromagnet coildiameters Rc are more than three times as long as the depth of the meltin said crucible at the beginning of pulling the single crystal.
 4. Amanufacturing apparatus of a single crystal according to claim 1,wherein electromagnets which form magnetic field of the same intensitydistribution are disposed symmetrically with respect to a central axisof said crucible.
 5. In a manufacturing apparatus of a single crystal bya horizontal magnetic field applied CZ method wherein a pair of coilsconstituting electromagnets of a magnetic field application apparatusare disposed interposing a crucible coaxial between the coils, and meansfor pulling the single crystal from a raw material melt in the cruciblewhile applying the horizontal magnetic field to the melt, wherein anelevating apparatus is disposed which is capable of finely adjusting thevertical position of said electromagnets relative to saidcrucible,wherein variation of width of the horizontal magnetic fieldintensity in the depth direction of the melt is controlled within arange of 0.8 to 1.2 times as wide as the average value of a horizontalmagnetic field intensity in the depth direction of melt on all linesperpendicular to the surface of the melt.
 6. In a manufacturingapparatus in accordance with claim 5, wherein said range is 0.85 to 1.15times as wide as the average value.
 7. A manufacturing apparatus inaccordance with claim 2, wherein the elevating apparatus is elevation ofthe crucible relative to the electromagnets.
 8. In a manufacturingmethod of a single crystal by a horizontal magnetic field applied CZmethod wherein a pair of coils constituting electromagnets of a magneticapplication apparatus are disposed interposing a crucible coaxialbetween the coils and the single crystal is pulled from a raw materialmelt in the crucible while applying a horizontal magnetic field to themelt; varying positions of electromagnets relative to the crucible areset so that the coils central axis Cc of the electromagnets pass throughthe central portion Cm in a depth direction of the melt in the crucible.